WIP - maintain foldmap with Buffer::edits_since

Max Brunsfeld and Nathan Sobo created

Co-Authored-By: Nathan Sobo <nathan@zed.dev>

Change summary

crates/editor/src/display_map.rs           |  52 +++++
crates/editor/src/display_map/block_map.rs |  17 +
crates/editor/src/display_map/fold_map.rs  | 183 ++++++++++-------------
crates/editor/src/display_map/tab_map.rs   |   2 
crates/editor/src/display_map/wrap_map.rs  |  21 +-
crates/editor/src/editor.rs                |   4 
crates/language/src/buffer.rs              |  10 
crates/language/src/tests.rs               |  27 +++
crates/project/src/worktree.rs             |  31 +++
crates/text/src/patch.rs                   |  76 ++++++---
crates/text/src/text.rs                    |  21 ++
11 files changed, 280 insertions(+), 164 deletions(-)

Detailed changes

crates/editor/src/display_map.rs 🔗

@@ -1,6 +1,5 @@
 mod block_map;
 mod fold_map;
-mod patch;
 mod tab_map;
 mod wrap_map;
 
@@ -11,9 +10,11 @@ use gpui::{
     fonts::{FontId, HighlightStyle},
     AppContext, Entity, ModelContext, ModelHandle,
 };
-use language::{Anchor, Buffer, Point, ToOffset, ToPoint};
+use language::{Anchor, Buffer, Patch, Point, ToOffset, ToPoint};
+use parking_lot::Mutex;
 use std::{
     collections::{HashMap, HashSet},
+    mem,
     ops::Range,
 };
 use sum_tree::Bias;
@@ -32,6 +33,7 @@ pub struct DisplayMap {
     tab_map: TabMap,
     wrap_map: ModelHandle<WrapMap>,
     block_map: BlockMap,
+    edits_since_sync: Mutex<Patch<usize>>,
 }
 
 impl Entity for DisplayMap {
@@ -52,17 +54,22 @@ impl DisplayMap {
         let (wrap_map, snapshot) = WrapMap::new(snapshot, font_id, font_size, wrap_width, cx);
         let block_map = BlockMap::new(buffer.clone(), snapshot);
         cx.observe(&wrap_map, |_, _, cx| cx.notify()).detach();
+        cx.subscribe(&buffer, Self::handle_buffer_event).detach();
         DisplayMap {
             buffer,
             fold_map,
             tab_map,
             wrap_map,
             block_map,
+            edits_since_sync: Default::default(),
         }
     }
 
     pub fn snapshot(&self, cx: &mut ModelContext<Self>) -> DisplayMapSnapshot {
-        let (folds_snapshot, edits) = self.fold_map.read(cx);
+        let (folds_snapshot, edits) = self.fold_map.read(
+            mem::take(&mut *self.edits_since_sync.lock()).into_inner(),
+            cx,
+        );
         let (tabs_snapshot, edits) = self.tab_map.sync(folds_snapshot.clone(), edits);
         let (wraps_snapshot, edits) = self
             .wrap_map
@@ -83,7 +90,10 @@ impl DisplayMap {
         ranges: impl IntoIterator<Item = Range<T>>,
         cx: &mut ModelContext<Self>,
     ) {
-        let (mut fold_map, snapshot, edits) = self.fold_map.write(cx);
+        let (mut fold_map, snapshot, edits) = self.fold_map.write(
+            mem::take(&mut *self.edits_since_sync.lock()).into_inner(),
+            cx,
+        );
         let (snapshot, edits) = self.tab_map.sync(snapshot, edits);
         let (snapshot, edits) = self
             .wrap_map
@@ -102,7 +112,10 @@ impl DisplayMap {
         ranges: impl IntoIterator<Item = Range<T>>,
         cx: &mut ModelContext<Self>,
     ) {
-        let (mut fold_map, snapshot, edits) = self.fold_map.write(cx);
+        let (mut fold_map, snapshot, edits) = self.fold_map.write(
+            mem::take(&mut *self.edits_since_sync.lock()).into_inner(),
+            cx,
+        );
         let (snapshot, edits) = self.tab_map.sync(snapshot, edits);
         let (snapshot, edits) = self
             .wrap_map
@@ -125,7 +138,10 @@ impl DisplayMap {
         P: ToOffset + Clone,
         T: Into<Rope> + Clone,
     {
-        let (snapshot, edits) = self.fold_map.read(cx);
+        let (snapshot, edits) = self.fold_map.read(
+            mem::take(&mut *self.edits_since_sync.lock()).into_inner(),
+            cx,
+        );
         let (snapshot, edits) = self.tab_map.sync(snapshot, edits);
         let (snapshot, edits) = self
             .wrap_map
@@ -143,7 +159,10 @@ impl DisplayMap {
     }
 
     pub fn remove_blocks(&mut self, ids: HashSet<BlockId>, cx: &mut ModelContext<Self>) {
-        let (snapshot, edits) = self.fold_map.read(cx);
+        let (snapshot, edits) = self.fold_map.read(
+            mem::take(&mut *self.edits_since_sync.lock()).into_inner(),
+            cx,
+        );
         let (snapshot, edits) = self.tab_map.sync(snapshot, edits);
         let (snapshot, edits) = self
             .wrap_map
@@ -166,6 +185,25 @@ impl DisplayMap {
     pub fn is_rewrapping(&self, cx: &gpui::AppContext) -> bool {
         self.wrap_map.read(cx).is_rewrapping()
     }
+
+    fn handle_buffer_event(
+        &mut self,
+        _: ModelHandle<Buffer>,
+        event: &language::Event,
+        _: &mut ModelContext<Self>,
+    ) {
+        match event {
+            language::Event::Edited(patch) => {
+                self.fold_map.version += 1;
+                let mut edits_since_sync = self.edits_since_sync.lock();
+                *edits_since_sync = edits_since_sync.compose(patch);
+            }
+            language::Event::Reparsed | language::Event::DiagnosticsUpdated => {
+                self.fold_map.version += 1;
+            }
+            _ => {}
+        }
+    }
 }
 
 pub struct DisplayMapSnapshot {

crates/editor/src/display_map/block_map.rs 🔗

@@ -1228,11 +1228,13 @@ mod tests {
 
         // Insert a line break, separating two block decorations into separate
         // lines.
-        buffer.update(cx, |buffer, cx| {
-            buffer.edit([Point::new(1, 1)..Point::new(1, 1)], "!!!\n", cx)
+        let buffer_edits = buffer.update(cx, |buffer, cx| {
+            let v0 = buffer.version();
+            buffer.edit([Point::new(1, 1)..Point::new(1, 1)], "!!!\n", cx);
+            buffer.edits_since(&v0).collect()
         });
 
-        let (folds_snapshot, fold_edits) = fold_map.read(cx);
+        let (folds_snapshot, fold_edits) = fold_map.read(buffer_edits, cx);
         let (tabs_snapshot, tab_edits) = tab_map.sync(folds_snapshot, fold_edits);
         let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
             wrap_map.sync(tabs_snapshot, tab_edits, cx)
@@ -1325,6 +1327,7 @@ mod tests {
         let mut expected_blocks = Vec::new();
 
         for _ in 0..operations {
+            let mut buffer_edits = Vec::new();
             match rng.gen_range(0..=100) {
                 0..=19 => {
                     let wrap_width = if rng.gen_bool(0.2) {
@@ -1375,7 +1378,7 @@ mod tests {
                         })
                         .collect::<Vec<_>>();
 
-                    let (folds_snapshot, fold_edits) = fold_map.read(cx);
+                    let (folds_snapshot, fold_edits) = fold_map.read(vec![], cx);
                     let (tabs_snapshot, tab_edits) = tab_map.sync(folds_snapshot, fold_edits);
                     let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
                         wrap_map.sync(tabs_snapshot, tab_edits, cx)
@@ -1396,7 +1399,7 @@ mod tests {
                         })
                         .collect();
 
-                    let (folds_snapshot, fold_edits) = fold_map.read(cx);
+                    let (folds_snapshot, fold_edits) = fold_map.read(vec![], cx);
                     let (tabs_snapshot, tab_edits) = tab_map.sync(folds_snapshot, fold_edits);
                     let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
                         wrap_map.sync(tabs_snapshot, tab_edits, cx)
@@ -1406,13 +1409,15 @@ mod tests {
                 }
                 _ => {
                     buffer.update(cx, |buffer, _| {
+                        let v0 = buffer.version();
                         buffer.randomly_edit(&mut rng, 1);
                         log::info!("buffer text: {:?}", buffer.text());
+                        buffer_edits.extend(buffer.edits_since(&v0));
                     });
                 }
             }
 
-            let (folds_snapshot, fold_edits) = fold_map.read(cx);
+            let (folds_snapshot, fold_edits) = fold_map.read(buffer_edits, cx);
             let (tabs_snapshot, tab_edits) = tab_map.sync(folds_snapshot, fold_edits);
             let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
                 wrap_map.sync(tabs_snapshot, tab_edits, cx)

crates/editor/src/display_map/fold_map.rs 🔗

@@ -1,11 +1,12 @@
 use gpui::{AppContext, ModelHandle};
-use language::{Anchor, AnchorRangeExt, Buffer, Chunk, Point, PointUtf16, TextSummary, ToOffset};
+use language::{
+    Anchor, AnchorRangeExt, Buffer, Chunk, Edit, Point, PointUtf16, TextSummary, ToOffset,
+};
 use parking_lot::Mutex;
 use std::{
     cmp::{self, Ordering},
-    iter, mem,
+    iter,
     ops::Range,
-    sync::atomic::{AtomicUsize, Ordering::SeqCst},
 };
 use sum_tree::{Bias, Cursor, FilterCursor, SumTree};
 use theme::SyntaxTheme;
@@ -131,12 +132,12 @@ impl<'a> FoldMapWriter<'a> {
         };
 
         consolidate_buffer_edits(&mut edits);
-        let edits = self.0.apply_edits(edits, cx);
+        let edits = self.0.sync(edits, cx);
         let snapshot = Snapshot {
             transforms: self.0.transforms.lock().clone(),
             folds: self.0.folds.clone(),
             buffer_snapshot: self.0.buffer.read(cx).snapshot(),
-            version: self.0.version.load(SeqCst),
+            version: self.0.version,
         };
         (snapshot, edits)
     }
@@ -150,7 +151,7 @@ impl<'a> FoldMapWriter<'a> {
         let mut fold_ixs_to_delete = Vec::new();
         let buffer = self.0.buffer.read(cx).snapshot();
         for range in ranges.into_iter() {
-            // Remove intersecting folds and add their ranges to edits that are passed to apply_edits.
+            // Remove intersecting folds and add their ranges to edits that are passed to sync.
             let mut folds_cursor = intersecting_folds(&buffer, &self.0.folds, range, true);
             while let Some(fold) = folds_cursor.item() {
                 let offset_range = fold.0.start.to_offset(&buffer)..fold.0.end.to_offset(&buffer);
@@ -178,12 +179,12 @@ impl<'a> FoldMapWriter<'a> {
         };
 
         consolidate_buffer_edits(&mut edits);
-        let edits = self.0.apply_edits(edits, cx);
+        let edits = self.0.sync(edits, cx);
         let snapshot = Snapshot {
             transforms: self.0.transforms.lock().clone(),
             folds: self.0.folds.clone(),
             buffer_snapshot: self.0.buffer.read(cx).snapshot(),
-            version: self.0.version.load(SeqCst),
+            version: self.0.version,
         };
         (snapshot, edits)
     }
@@ -193,15 +194,7 @@ pub struct FoldMap {
     buffer: ModelHandle<Buffer>,
     transforms: Mutex<SumTree<Transform>>,
     folds: SumTree<Fold>,
-    last_sync: Mutex<SyncState>,
-    version: AtomicUsize,
-}
-
-#[derive(Clone)]
-struct SyncState {
-    version: clock::Global,
-    parse_count: usize,
-    diagnostics_update_count: usize,
+    pub version: usize,
 }
 
 impl FoldMap {
@@ -220,60 +213,33 @@ impl FoldMap {
                 },
                 &(),
             )),
-            last_sync: Mutex::new(SyncState {
-                version: buffer.version(),
-                parse_count: buffer.parse_count(),
-                diagnostics_update_count: buffer.diagnostics_update_count(),
-            }),
-            version: AtomicUsize::new(0),
+            version: 0,
         };
-        let (snapshot, _) = this.read(cx);
+        let (snapshot, _) = this.read(Vec::new(), cx);
         (this, snapshot)
     }
 
-    pub fn read(&self, cx: &AppContext) -> (Snapshot, Vec<FoldEdit>) {
-        let edits = self.sync(cx);
+    pub fn read(&self, edits: Vec<Edit<usize>>, cx: &AppContext) -> (Snapshot, Vec<FoldEdit>) {
+        let edits = self.sync(edits, cx);
         self.check_invariants(cx);
         let snapshot = Snapshot {
             transforms: self.transforms.lock().clone(),
             folds: self.folds.clone(),
             buffer_snapshot: self.buffer.read(cx).snapshot(),
-            version: self.version.load(SeqCst),
+            version: self.version,
         };
         (snapshot, edits)
     }
 
-    pub fn write(&mut self, cx: &AppContext) -> (FoldMapWriter, Snapshot, Vec<FoldEdit>) {
-        let (snapshot, edits) = self.read(cx);
+    pub fn write(
+        &mut self,
+        edits: Vec<Edit<usize>>,
+        cx: &AppContext,
+    ) -> (FoldMapWriter, Snapshot, Vec<FoldEdit>) {
+        let (snapshot, edits) = self.read(edits, cx);
         (FoldMapWriter(self), snapshot, edits)
     }
 
-    fn sync(&self, cx: &AppContext) -> Vec<FoldEdit> {
-        let buffer = self.buffer.read(cx);
-        let last_sync = mem::replace(
-            &mut *self.last_sync.lock(),
-            SyncState {
-                version: buffer.version(),
-                parse_count: buffer.parse_count(),
-                diagnostics_update_count: buffer.diagnostics_update_count(),
-            },
-        );
-        let edits = buffer
-            .edits_since(&last_sync.version)
-            .map(Into::into)
-            .collect::<Vec<_>>();
-        if edits.is_empty() {
-            if last_sync.parse_count != buffer.parse_count()
-                || last_sync.diagnostics_update_count != buffer.diagnostics_update_count()
-            {
-                self.version.fetch_add(1, SeqCst);
-            }
-            Vec::new()
-        } else {
-            self.apply_edits(edits, cx)
-        }
-    }
-
     fn check_invariants(&self, cx: &AppContext) {
         if cfg!(test) {
             let buffer = self.buffer.read(cx);
@@ -285,7 +251,11 @@ impl FoldMap {
         }
     }
 
-    fn apply_edits(&self, buffer_edits: Vec<text::Edit<usize>>, cx: &AppContext) -> Vec<FoldEdit> {
+    fn sync(&self, buffer_edits: Vec<text::Edit<usize>>, cx: &AppContext) -> Vec<FoldEdit> {
+        if buffer_edits.is_empty() {
+            return Vec::new();
+        }
+
         let buffer = self.buffer.read(cx).snapshot();
         let mut buffer_edits_iter = buffer_edits.iter().cloned().peekable();
 
@@ -479,7 +449,6 @@ impl FoldMap {
         }
 
         *transforms = new_transforms;
-        self.version.fetch_add(1, SeqCst);
         fold_edits
     }
 }
@@ -1086,7 +1055,7 @@ mod tests {
         let buffer = cx.add_model(|cx| Buffer::new(0, sample_text(5, 6), cx));
         let mut map = FoldMap::new(buffer.clone(), cx.as_ref()).0;
 
-        let (mut writer, _, _) = map.write(cx.as_ref());
+        let (mut writer, _, _) = map.write(vec![], cx.as_ref());
         let (snapshot2, edits) = writer.fold(
             vec![
                 Point::new(0, 2)..Point::new(2, 2),
@@ -1109,7 +1078,8 @@ mod tests {
             ]
         );
 
-        buffer.update(cx, |buffer, cx| {
+        let edits = buffer.update(cx, |buffer, cx| {
+            let v0 = buffer.version();
             buffer.edit(
                 vec![
                     Point::new(0, 0)..Point::new(0, 1),
@@ -1118,8 +1088,9 @@ mod tests {
                 "123",
                 cx,
             );
+            buffer.edits_since(&v0).collect()
         });
-        let (snapshot3, edits) = map.read(cx.as_ref());
+        let (snapshot3, edits) = map.read(edits, cx.as_ref());
         assert_eq!(snapshot3.text(), "123a…c123c…eeeee");
         assert_eq!(
             edits,
@@ -1135,15 +1106,17 @@ mod tests {
             ]
         );
 
-        buffer.update(cx, |buffer, cx| {
-            buffer.edit(vec![Point::new(2, 6)..Point::new(4, 3)], "456", cx)
+        let edits = buffer.update(cx, |buffer, cx| {
+            let v0 = buffer.version();
+            buffer.edit(vec![Point::new(2, 6)..Point::new(4, 3)], "456", cx);
+            buffer.edits_since(&v0).collect()
         });
-        let (snapshot4, _) = map.read(cx.as_ref());
+        let (snapshot4, _) = map.read(edits, cx.as_ref());
         assert_eq!(snapshot4.text(), "123a…c123456eee");
 
-        let (mut writer, _, _) = map.write(cx.as_ref());
+        let (mut writer, _, _) = map.write(vec![], cx.as_ref());
         writer.unfold(Some(Point::new(0, 4)..Point::new(0, 5)), cx.as_ref());
-        let (snapshot5, _) = map.read(cx.as_ref());
+        let (snapshot5, _) = map.read(vec![], cx.as_ref());
         assert_eq!(snapshot5.text(), "123aaaaa\nbbbbbb\nccc123456eee");
     }
 
@@ -1154,21 +1127,21 @@ mod tests {
         {
             let mut map = FoldMap::new(buffer.clone(), cx.as_ref()).0;
 
-            let (mut writer, _, _) = map.write(cx.as_ref());
+            let (mut writer, _, _) = map.write(vec![], cx.as_ref());
             writer.fold(vec![5..8], cx.as_ref());
-            let (snapshot, _) = map.read(cx.as_ref());
+            let (snapshot, _) = map.read(vec![], cx.as_ref());
             assert_eq!(snapshot.text(), "abcde…ijkl");
 
             // Create an fold adjacent to the start of the first fold.
-            let (mut writer, _, _) = map.write(cx.as_ref());
+            let (mut writer, _, _) = map.write(vec![], cx.as_ref());
             writer.fold(vec![0..1, 2..5], cx.as_ref());
-            let (snapshot, _) = map.read(cx.as_ref());
+            let (snapshot, _) = map.read(vec![], cx.as_ref());
             assert_eq!(snapshot.text(), "…b…ijkl");
 
             // Create an fold adjacent to the end of the first fold.
-            let (mut writer, _, _) = map.write(cx.as_ref());
+            let (mut writer, _, _) = map.write(vec![], cx.as_ref());
             writer.fold(vec![11..11, 8..10], cx.as_ref());
-            let (snapshot, _) = map.read(cx.as_ref());
+            let (snapshot, _) = map.read(vec![], cx.as_ref());
             assert_eq!(snapshot.text(), "…b…kl");
         }
 
@@ -1176,14 +1149,18 @@ mod tests {
             let mut map = FoldMap::new(buffer.clone(), cx.as_ref()).0;
 
             // Create two adjacent folds.
-            let (mut writer, _, _) = map.write(cx.as_ref());
+            let (mut writer, _, _) = map.write(vec![], cx.as_ref());
             writer.fold(vec![0..2, 2..5], cx.as_ref());
-            let (snapshot, _) = map.read(cx.as_ref());
+            let (snapshot, _) = map.read(vec![], cx.as_ref());
             assert_eq!(snapshot.text(), "…fghijkl");
 
             // Edit within one of the folds.
-            buffer.update(cx, |buffer, cx| buffer.edit(vec![0..1], "12345", cx));
-            let (snapshot, _) = map.read(cx.as_ref());
+            let edits = buffer.update(cx, |buffer, cx| {
+                let v0 = buffer.version();
+                buffer.edit(vec![0..1], "12345", cx);
+                buffer.edits_since(&v0).collect()
+            });
+            let (snapshot, _) = map.read(edits, cx.as_ref());
             assert_eq!(snapshot.text(), "12345…fghijkl");
         }
     }
@@ -1192,7 +1169,7 @@ mod tests {
     fn test_overlapping_folds(cx: &mut gpui::MutableAppContext) {
         let buffer = cx.add_model(|cx| Buffer::new(0, sample_text(5, 6), cx));
         let mut map = FoldMap::new(buffer.clone(), cx.as_ref()).0;
-        let (mut writer, _, _) = map.write(cx.as_ref());
+        let (mut writer, _, _) = map.write(vec![], cx.as_ref());
         writer.fold(
             vec![
                 Point::new(0, 2)..Point::new(2, 2),
@@ -1202,7 +1179,7 @@ mod tests {
             ],
             cx.as_ref(),
         );
-        let (snapshot, _) = map.read(cx.as_ref());
+        let (snapshot, _) = map.read(vec![], cx.as_ref());
         assert_eq!(snapshot.text(), "aa…eeeee");
     }
 
@@ -1211,7 +1188,7 @@ mod tests {
         let buffer = cx.add_model(|cx| Buffer::new(0, sample_text(5, 6), cx));
         let mut map = FoldMap::new(buffer.clone(), cx.as_ref()).0;
 
-        let (mut writer, _, _) = map.write(cx.as_ref());
+        let (mut writer, _, _) = map.write(vec![], cx.as_ref());
         writer.fold(
             vec![
                 Point::new(0, 2)..Point::new(2, 2),
@@ -1219,13 +1196,15 @@ mod tests {
             ],
             cx.as_ref(),
         );
-        let (snapshot, _) = map.read(cx.as_ref());
+        let (snapshot, _) = map.read(vec![], cx.as_ref());
         assert_eq!(snapshot.text(), "aa…cccc\nd…eeeee");
 
-        buffer.update(cx, |buffer, cx| {
-            buffer.edit(Some(Point::new(2, 2)..Point::new(3, 1)), "", cx)
+        let edits = buffer.update(cx, |buffer, cx| {
+            let v0 = buffer.version();
+            buffer.edit(Some(Point::new(2, 2)..Point::new(3, 1)), "", cx);
+            buffer.edits_since(&v0).collect()
         });
-        let (snapshot, _) = map.read(cx.as_ref());
+        let (snapshot, _) = map.read(edits, cx.as_ref());
         assert_eq!(snapshot.text(), "aa…eeeee");
     }
 
@@ -1235,7 +1214,7 @@ mod tests {
         let mut map = FoldMap::new(buffer.clone(), cx.as_ref()).0;
         let buffer = buffer.read(cx);
 
-        let (mut writer, _, _) = map.write(cx.as_ref());
+        let (mut writer, _, _) = map.write(vec![], cx.as_ref());
         writer.fold(
             vec![
                 Point::new(0, 2)..Point::new(2, 2),
@@ -1245,7 +1224,7 @@ mod tests {
             ],
             cx.as_ref(),
         );
-        let (snapshot, _) = map.read(cx.as_ref());
+        let (snapshot, _) = map.read(vec![], cx.as_ref());
         let fold_ranges = snapshot
             .folds_in_range(Point::new(1, 0)..Point::new(1, 3))
             .map(|fold| fold.start.to_point(buffer)..fold.end.to_point(buffer))
@@ -1272,27 +1251,27 @@ mod tests {
         });
         let mut map = FoldMap::new(buffer.clone(), cx.as_ref()).0;
 
-        let (mut initial_snapshot, _) = map.read(cx.as_ref());
+        let (mut initial_snapshot, _) = map.read(vec![], cx.as_ref());
         let mut snapshot_edits = Vec::new();
 
         for _ in 0..operations {
             log::info!("text: {:?}", buffer.read(cx).text());
-            match rng.gen_range(0..=100) {
+            let buffer_edits = match rng.gen_range(0..=100) {
                 0..=59 => {
                     snapshot_edits.extend(map.randomly_mutate(&mut rng, cx.as_ref()));
+                    vec![]
                 }
-                _ => {
-                    let edits = buffer.update(cx, |buffer, _| {
-                        let start_version = buffer.version.clone();
-                        let edit_count = rng.gen_range(1..=5);
-                        buffer.randomly_edit(&mut rng, edit_count);
-                        buffer
-                            .edits_since::<Point>(&start_version)
-                            .collect::<Vec<_>>()
-                    });
+                _ => buffer.update(cx, |buffer, _| {
+                    let start_version = buffer.version.clone();
+                    let edit_count = rng.gen_range(1..=5);
+                    buffer.randomly_edit(&mut rng, edit_count);
+                    let edits = buffer
+                        .edits_since::<Point>(&start_version)
+                        .collect::<Vec<_>>();
                     log::info!("editing {:?}", edits);
-                }
-            }
+                    buffer.edits_since::<usize>(&start_version).collect()
+                }),
+            };
 
             let buffer = map.buffer.read(cx).snapshot();
             let mut expected_text: String = buffer.text().to_string();
@@ -1309,7 +1288,7 @@ mod tests {
             expected_buffer_rows.extend((0..=next_row).rev());
             expected_buffer_rows.reverse();
 
-            let (snapshot, edits) = map.read(cx.as_ref());
+            let (snapshot, edits) = map.read(buffer_edits, cx.as_ref());
             assert_eq!(snapshot.text(), expected_text);
             snapshot_edits.push((snapshot.clone(), edits));
 
@@ -1479,7 +1458,7 @@ mod tests {
 
         let mut map = FoldMap::new(buffer.clone(), cx.as_ref()).0;
 
-        let (mut writer, _, _) = map.write(cx.as_ref());
+        let (mut writer, _, _) = map.write(vec![], cx.as_ref());
         writer.fold(
             vec![
                 Point::new(0, 2)..Point::new(2, 2),
@@ -1488,7 +1467,7 @@ mod tests {
             cx.as_ref(),
         );
 
-        let (snapshot, _) = map.read(cx.as_ref());
+        let (snapshot, _) = map.read(vec![], cx.as_ref());
         assert_eq!(snapshot.text(), "aa…cccc\nd…eeeee\nffffff\n");
         assert_eq!(snapshot.buffer_rows(0).collect::<Vec<_>>(), [0, 3, 5, 6]);
         assert_eq!(snapshot.buffer_rows(3).collect::<Vec<_>>(), [6]);
@@ -1540,7 +1519,7 @@ mod tests {
                         to_unfold.push(start..end);
                     }
                     log::info!("unfolding {:?}", to_unfold);
-                    let (mut writer, snapshot, edits) = self.write(cx.as_ref());
+                    let (mut writer, snapshot, edits) = self.write(vec![], cx.as_ref());
                     snapshot_edits.push((snapshot, edits));
                     let (snapshot, edits) = writer.fold(to_unfold, cx.as_ref());
                     snapshot_edits.push((snapshot, edits));
@@ -1554,7 +1533,7 @@ mod tests {
                         to_fold.push(start..end);
                     }
                     log::info!("folding {:?}", to_fold);
-                    let (mut writer, snapshot, edits) = self.write(cx.as_ref());
+                    let (mut writer, snapshot, edits) = self.write(vec![], cx.as_ref());
                     snapshot_edits.push((snapshot, edits));
                     let (snapshot, edits) = writer.fold(to_fold, cx.as_ref());
                     snapshot_edits.push((snapshot, edits));

crates/editor/src/display_map/tab_map.rs 🔗

@@ -474,7 +474,7 @@ mod tests {
 
         let (mut fold_map, _) = FoldMap::new(buffer.clone(), cx);
         fold_map.randomly_mutate(&mut rng, cx);
-        let (folds_snapshot, _) = fold_map.read(cx);
+        let (folds_snapshot, _) = fold_map.read(vec![], cx);
         log::info!("FoldMap text: {:?}", folds_snapshot.text());
 
         let (_, tabs_snapshot) = TabMap::new(folds_snapshot.clone(), tab_size);

crates/editor/src/display_map/wrap_map.rs 🔗

@@ -1,6 +1,5 @@
 use super::{
     fold_map,
-    patch::Patch,
     tab_map::{self, Edit as TabEdit, Snapshot as TabSnapshot, TabPoint},
     DisplayRow,
 };
@@ -13,6 +12,7 @@ use lazy_static::lazy_static;
 use smol::future::yield_now;
 use std::{collections::VecDeque, mem, ops::Range, time::Duration};
 use sum_tree::{Bias, Cursor, SumTree};
+use text::Patch;
 use theme::SyntaxTheme;
 
 pub use super::tab_map::TextSummary;
@@ -21,8 +21,8 @@ pub type Edit = text::Edit<u32>;
 pub struct WrapMap {
     snapshot: Snapshot,
     pending_edits: VecDeque<(TabSnapshot, Vec<TabEdit>)>,
-    interpolated_edits: Patch,
-    edits_since_sync: Patch,
+    interpolated_edits: Patch<u32>,
+    edits_since_sync: Patch<u32>,
     wrap_width: Option<f32>,
     background_task: Option<Task<()>>,
     font: (FontId, f32),
@@ -308,7 +308,7 @@ impl Snapshot {
         }
     }
 
-    fn interpolate(&mut self, new_tab_snapshot: TabSnapshot, tab_edits: &[TabEdit]) -> Patch {
+    fn interpolate(&mut self, new_tab_snapshot: TabSnapshot, tab_edits: &[TabEdit]) -> Patch<u32> {
         let mut new_transforms;
         if tab_edits.is_empty() {
             new_transforms = self.transforms.clone();
@@ -383,7 +383,7 @@ impl Snapshot {
         tab_edits: &[TabEdit],
         wrap_width: f32,
         line_wrapper: &mut LineWrapper,
-    ) -> Patch {
+    ) -> Patch<u32> {
         #[derive(Debug)]
         struct RowEdit {
             old_rows: Range<u32>,
@@ -526,7 +526,7 @@ impl Snapshot {
         old_snapshot.compute_edits(tab_edits, self)
     }
 
-    fn compute_edits(&self, tab_edits: &[TabEdit], new_snapshot: &Snapshot) -> Patch {
+    fn compute_edits(&self, tab_edits: &[TabEdit], new_snapshot: &Snapshot) -> Patch<u32> {
         let mut wrap_edits = Vec::new();
         let mut old_cursor = self.transforms.cursor::<TransformSummary>();
         let mut new_cursor = new_snapshot.transforms.cursor::<TransformSummary>();
@@ -1067,6 +1067,7 @@ mod tests {
         for _i in 0..operations {
             log::info!("{} ==============================================", _i);
 
+            let mut buffer_edits = Vec::new();
             match rng.gen_range(0..=100) {
                 0..=19 => {
                     wrap_width = if rng.gen_bool(0.2) {
@@ -1090,7 +1091,11 @@ mod tests {
                     }
                 }
                 _ => {
-                    buffer.update(&mut cx, |buffer, _| buffer.randomly_mutate(&mut rng));
+                    buffer.update(&mut cx, |buffer, _| {
+                        let v0 = buffer.version();
+                        buffer.randomly_mutate(&mut rng);
+                        buffer_edits.extend(buffer.edits_since(&v0));
+                    });
                 }
             }
 
@@ -1098,7 +1103,7 @@ mod tests {
                 "Unwrapped text (no folds): {:?}",
                 buffer.read_with(&cx, |buf, _| buf.text())
             );
-            let (folds_snapshot, fold_edits) = cx.read(|cx| fold_map.read(cx));
+            let (folds_snapshot, fold_edits) = cx.read(|cx| fold_map.read(buffer_edits, cx));
             log::info!(
                 "Unwrapped text (unexpanded tabs): {:?}",
                 folds_snapshot.text()

crates/editor/src/editor.rs 🔗

@@ -3466,13 +3466,13 @@ impl Editor {
         cx: &mut ViewContext<Self>,
     ) {
         match event {
-            language::Event::Edited => cx.emit(Event::Edited),
+            language::Event::Edited(_) => cx.emit(Event::Edited),
             language::Event::Dirtied => cx.emit(Event::Dirtied),
             language::Event::Saved => cx.emit(Event::Saved),
             language::Event::FileHandleChanged => cx.emit(Event::FileHandleChanged),
             language::Event::Reloaded => cx.emit(Event::FileHandleChanged),
             language::Event::Closed => cx.emit(Event::Closed),
-            language::Event::Reparsed => {}
+            _ => {}
         }
     }
 

crates/language/src/buffer.rs 🔗

@@ -107,12 +107,13 @@ pub enum Operation {
 
 #[derive(Clone, Debug, Eq, PartialEq)]
 pub enum Event {
-    Edited,
+    Edited(Patch<usize>),
     Dirtied,
     Saved,
     FileHandleChanged,
     Reloaded,
     Reparsed,
+    DiagnosticsUpdated,
     Closed,
 }
 
@@ -805,6 +806,7 @@ impl Buffer {
 
         self.diagnostics_update_count += 1;
         cx.notify();
+        cx.emit(Event::DiagnosticsUpdated);
         Ok(Operation::UpdateDiagnostics(self.diagnostics.clone()))
     }
 
@@ -1316,14 +1318,16 @@ impl Buffer {
         was_dirty: bool,
         cx: &mut ModelContext<Self>,
     ) {
-        if self.edits_since::<usize>(old_version).next().is_none() {
+        let patch =
+            unsafe { Patch::new_unchecked(self.edits_since::<usize>(old_version).collect()) };
+        if patch.is_empty() {
             return;
         }
 
         self.reparse(cx);
         self.update_language_server();
 
-        cx.emit(Event::Edited);
+        cx.emit(Event::Edited(patch));
         if !was_dirty {
             cx.emit(Event::Dirtied);
         }

crates/language/src/tests.rs 🔗

@@ -110,11 +110,34 @@ fn test_edit_events(cx: &mut gpui::MutableAppContext) {
     let buffer_1_events = buffer_1_events.borrow();
     assert_eq!(
         *buffer_1_events,
-        vec![Event::Edited, Event::Dirtied, Event::Edited, Event::Edited]
+        vec![
+            Event::Edited(Patch::new(vec![Edit {
+                old: 2..4,
+                new: 2..5
+            }])),
+            Event::Dirtied,
+            Event::Edited(Patch::new(vec![Edit {
+                old: 5..5,
+                new: 5..7
+            }])),
+            Event::Edited(Patch::new(vec![Edit {
+                old: 5..7,
+                new: 5..5,
+            }]))
+        ]
     );
 
     let buffer_2_events = buffer_2_events.borrow();
-    assert_eq!(*buffer_2_events, vec![Event::Edited, Event::Dirtied]);
+    assert_eq!(
+        *buffer_2_events,
+        vec![
+            Event::Edited(Patch::new(vec![Edit {
+                old: 2..4,
+                new: 2..5
+            }])),
+            Event::Dirtied
+        ]
+    );
 }
 
 #[gpui::test]

crates/project/src/worktree.rs 🔗

@@ -20,7 +20,6 @@ use postage::{
     prelude::{Sink as _, Stream as _},
     watch,
 };
-
 use serde::Deserialize;
 use smol::channel::{self, Sender};
 use std::{
@@ -3017,7 +3016,7 @@ mod tests {
         fmt::Write,
         time::{SystemTime, UNIX_EPOCH},
     };
-    use text::Point;
+    use text::{Patch, Point};
     use util::test::temp_tree;
 
     #[gpui::test]
@@ -3470,7 +3469,13 @@ mod tests {
             assert!(buffer.is_dirty());
             assert_eq!(
                 *events.borrow(),
-                &[language::Event::Edited, language::Event::Dirtied]
+                &[
+                    language::Event::Edited(Patch::new(vec![text::Edit {
+                        old: 1..2,
+                        new: 1..1
+                    }])),
+                    language::Event::Dirtied
+                ]
             );
             events.borrow_mut().clear();
             buffer.did_save(buffer.version(), buffer.file().unwrap().mtime(), None, cx);
@@ -3493,21 +3498,33 @@ mod tests {
             assert_eq!(
                 *events.borrow(),
                 &[
-                    language::Event::Edited,
+                    language::Event::Edited(Patch::new(vec![text::Edit {
+                        old: 1..1,
+                        new: 1..2
+                    }])),
                     language::Event::Dirtied,
-                    language::Event::Edited
+                    language::Event::Edited(Patch::new(vec![text::Edit {
+                        old: 2..2,
+                        new: 2..3
+                    }])),
                 ],
             );
             events.borrow_mut().clear();
 
             // TODO - currently, after restoring the buffer to its
             // previously-saved state, the is still considered dirty.
-            buffer.edit(vec![1..3], "", cx);
+            buffer.edit([1..3], "", cx);
             assert!(buffer.text() == "ac");
             assert!(buffer.is_dirty());
         });
 
-        assert_eq!(*events.borrow(), &[language::Event::Edited]);
+        assert_eq!(
+            *events.borrow(),
+            &[language::Event::Edited(Patch::new(vec![text::Edit {
+                old: 1..3,
+                new: 1..1
+            }]))]
+        );
 
         // When a file is deleted, the buffer is considered dirty.
         let events = Rc::new(RefCell::new(Vec::new()));

crates/editor/src/display_map/patch.rs → crates/text/src/patch.rs 🔗

@@ -1,16 +1,40 @@
-use std::{cmp, mem};
-
-type Edit = text::Edit<u32>;
-
-#[derive(Default, Debug, PartialEq, Eq)]
-pub struct Patch(Vec<Edit>);
+use crate::Edit;
+use std::{
+    cmp, mem,
+    ops::{Add, AddAssign, Sub},
+};
+
+#[derive(Clone, Default, Debug, PartialEq, Eq)]
+pub struct Patch<T>(Vec<Edit<T>>);
+
+impl<T> Patch<T>
+where
+    T: Clone
+        + Copy
+        + Ord
+        + Sub<T, Output = T>
+        + Add<T, Output = T>
+        + AddAssign
+        + Default
+        + PartialEq,
+{
+    pub unsafe fn new_unchecked(edits: Vec<Edit<T>>) -> Self {
+        Self(edits)
+    }
 
-impl Patch {
-    pub unsafe fn new_unchecked(edits: Vec<Edit>) -> Self {
+    pub fn new(edits: Vec<Edit<T>>) -> Self {
+        let mut last_edit: Option<&Edit<T>> = None;
+        for edit in &edits {
+            if let Some(last_edit) = last_edit {
+                assert!(edit.old.start > last_edit.old.end);
+                assert!(edit.new.start > last_edit.new.end);
+            }
+            last_edit = Some(edit);
+        }
         Self(edits)
     }
 
-    pub fn into_inner(self) -> Vec<Edit> {
+    pub fn into_inner(self) -> Vec<Edit<T>> {
         self.0
     }
 
@@ -19,8 +43,8 @@ impl Patch {
         let mut new_edits_iter = other.0.iter().cloned().peekable();
         let mut composed = Patch(Vec::new());
 
-        let mut old_start = 0;
-        let mut new_start = 0;
+        let mut old_start = T::default();
+        let mut new_start = T::default();
         loop {
             let old_edit = old_edits_iter.peek_mut();
             let new_edit = new_edits_iter.peek_mut();
@@ -33,8 +57,8 @@ impl Patch {
                     old_start += catchup;
                     new_start += catchup;
 
-                    let old_end = old_start + old_edit.old.len() as u32;
-                    let new_end = new_start + old_edit.new.len() as u32;
+                    let old_end = old_start + old_edit.old_len();
+                    let new_end = new_start + old_edit.new_len();
                     composed.push(Edit {
                         old: old_start..old_end,
                         new: new_start..new_end,
@@ -54,8 +78,8 @@ impl Patch {
                     old_start += catchup;
                     new_start += catchup;
 
-                    let old_end = old_start + new_edit.old.len() as u32;
-                    let new_end = new_start + new_edit.new.len() as u32;
+                    let old_end = old_start + new_edit.old_len();
+                    let new_end = new_start + new_edit.new_len();
                     composed.push(Edit {
                         old: old_start..old_end,
                         new: new_start..new_end,
@@ -106,9 +130,8 @@ impl Patch {
                 }
 
                 if old_edit.new.end > new_edit.old.end {
-                    let old_end =
-                        old_start + cmp::min(old_edit.old.len() as u32, new_edit.old.len() as u32);
-                    let new_end = new_start + new_edit.new.len() as u32;
+                    let old_end = old_start + cmp::min(old_edit.old_len(), new_edit.old_len());
+                    let new_end = new_start + new_edit.new_len();
                     composed.push(Edit {
                         old: old_start..old_end,
                         new: new_start..new_end,
@@ -120,9 +143,8 @@ impl Patch {
                     new_start = new_end;
                     new_edits_iter.next();
                 } else {
-                    let old_end = old_start + old_edit.old.len() as u32;
-                    let new_end =
-                        new_start + cmp::min(old_edit.new.len() as u32, new_edit.new.len() as u32);
+                    let old_end = old_start + old_edit.old_len();
+                    let new_end = new_start + cmp::min(old_edit.new_len(), new_edit.new_len());
                     composed.push(Edit {
                         old: old_start..old_end,
                         new: new_start..new_end,
@@ -153,8 +175,12 @@ impl Patch {
         self.0.clear();
     }
 
-    fn push(&mut self, edit: Edit) {
-        if edit.old.len() == 0 && edit.new.len() == 0 {
+    pub fn is_empty(&self) -> bool {
+        self.0.is_empty()
+    }
+
+    fn push(&mut self, edit: Edit<T>) {
+        if edit.is_empty() {
             return;
         }
 
@@ -479,7 +505,7 @@ mod tests {
     }
 
     #[track_caller]
-    fn assert_patch_composition(old: Patch, new: Patch, composed: Patch) {
+    fn assert_patch_composition(old: Patch<u32>, new: Patch<u32>, composed: Patch<u32>) {
         let original = ('a'..'z').collect::<Vec<_>>();
         let inserted = ('A'..'Z').collect::<Vec<_>>();
 
@@ -498,7 +524,7 @@ mod tests {
         assert_eq!(old.compose(&new), composed);
     }
 
-    fn apply_patch(text: &mut Vec<char>, patch: &Patch, new_text: &[char]) {
+    fn apply_patch(text: &mut Vec<char>, patch: &Patch<u32>, new_text: &[char]) {
         for edit in patch.0.iter().rev() {
             text.splice(
                 edit.old.start as usize..edit.old.end as usize,

crates/text/src/text.rs 🔗

@@ -1,5 +1,6 @@
 mod anchor;
 mod operation_queue;
+mod patch;
 mod point;
 mod point_utf16;
 #[cfg(any(test, feature = "test-support"))]
@@ -14,6 +15,7 @@ use anyhow::{anyhow, Result};
 use clock::ReplicaId;
 use collections::{HashMap, HashSet};
 use operation_queue::OperationQueue;
+pub use patch::Patch;
 pub use point::*;
 pub use point_utf16::*;
 #[cfg(any(test, feature = "test-support"))]
@@ -24,7 +26,7 @@ pub use selection::*;
 use std::{
     cmp::{self, Reverse},
     iter::Iterator,
-    ops::{self, Deref, Range},
+    ops::{self, Deref, Range, Sub},
     str,
     sync::Arc,
     time::{Duration, Instant},
@@ -307,6 +309,23 @@ pub struct Edit<D> {
     pub new: Range<D>,
 }
 
+impl<D> Edit<D>
+where
+    D: Sub<D, Output = D> + PartialEq + Copy,
+{
+    pub fn old_len(&self) -> D {
+        self.old.end - self.old.start
+    }
+
+    pub fn new_len(&self) -> D {
+        self.new.end - self.new.start
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.old.start == self.old.end && self.new.start == self.new.end
+    }
+}
+
 impl<D1, D2> Edit<(D1, D2)> {
     pub fn flatten(self) -> (Edit<D1>, Edit<D2>) {
         (